This invention relates to a wound section for an AC capacitor, particularly a motor-start capacitor, in which the anodized electrode foils are wound so that the leading ends are even thus reducing the power factor of a capacitor containing such a wound section.
In order to obtain evenly and smoothly wound sections, it has been customary to start the separator strips and the end of one foil electrode and wind them a few turns to anchor the foil before starting the next foil electrode. Since the first foil and separator strips are under winding tension, they serve to keep the second one in place and assure its even take-up into the wound section. Unfortunately, this arrangement leads to high resistance fringing and a high power factor in AC capacitors.
When the section is being wound for a DC capacitor, it is customary to use a longer cathode strip, and this is the strip started first. Since cathode foil is not anodized, it is less expensive and the additional cathode foil length contributes little to the cost of the capacitor. However, for AC capacitors, both foils are anodized as they alternately serve as anodes, and the additional length of anodized foil used as a lead in for winding does contribute to the cost of the section.